The U.S. practically begged Russia to invade Ukraine. From Caitlin Johnstone at caitlinjohnstone.com:

Vladimir Putin has approved the annexation of four territories in eastern Ukraine, whose addition to the Russian Federation now await authorization from Russia’s other branches of government.
The Zelensky government responded to the move by applying to join NATO, only to be immediately shut down by US and NATO officials. Can’t have sacrificial pawns trying to rise above their station on the grand chessboard, after all.
But the empire’s proxy war against Russia continues, and the Ukrainian government has announced its intentions to drive out Russia from all of the Ukrainian territories it has claimed as its own.
“For our plans, [Russia’s annexation] doesn’t matter,” Zelensky advisor Mykhailo Podolyak told Politico, adding that Ukraine will “protect our land using all our forces” and “should liberate all its territories.”
The plan to reclaim territories annexed by Russia will according to Zelensky also include Crimea, which was annexed in 2014.
All this talk about preparing a massive western-backed counter-offensive to recapture annexed territories from Russia — whose ranks are being reinforced with an additional 300,000 reservists — comes as Putin suggests that nuclear weapons may be used to protect what Moscow considers parts of Russia. Russia, like the United States, is one of the nuclear-armed nations without a No First Use policy.